issues and experts
Genetic research sheds light on sudden unexplained death in the young
Informing a grieving family that their child has suddenly died of unexplainable causes is a painful task for all coroners. Yet that’s the sad reality in an estimated 700 pediatric deaths each year in Canada.
But recent SFU alumna Laura Dewar, a former B.C. coroner who graduated from SFU last December with a PhD in biomedical physiology and kinesiology, says her thesis research, published in Circulation: Cardiovascular Genetics, has revealed some promising clues about the cause of these deaths.
SUDY refers to cases where an apparently healthy person with no previous diagnosis of a life-threatening disease suddenly dies for no apparent reason. In about one-third of adult SUDY cases (up to age 40 or even 50 years), and in up to 80 per cent of infant SUDY cases, an autopsy fails to reveal a cause of death.
“Nothing shows up in an autopsy, or in ancillary tests such as biochemical analyses or toxicology,” says Dewar who, after 24 years as a coroner felt she had to find some answers. She wondered whether a genetic component might be responsible, and decided to return to graduate school to research the possibility.
Working with SFU professor Glen Tibbits, an expert in pediatric cardiac physiology, Dewar concentrated her PhD research on the potential genetic causes of SUDY. One known underlying cause is sudden cardiac arrest due to inherited heart rhythm disorders, such as long QT syndrome. She focused on finding genetic variants in a number of different genes associated with inherited heart rhythm disorders, but also included genes that no-one had yet examined.
“I found one particular variant in a gene that has not been previously investigated, and there is now ongoing research at SFU using stem cells to see if it could be a potential cause of SUDY,” she says.
Dewar has also developed some post-mortem guidelines she hopes coroners and medical examiners will adopt when dealing with SUDY. “We need to ensure that, in these cases, post-mortem tissue is retained after the autopsy so that future genetic testing can be done. When a family loses a child and there are no answers, it’s important to ask them to be clinically assessed by experts in SUDY so that the immediate family is not at risk for another tragic death.
“Clinical tests (including genetic testing of both the living and deceased relatives) can unmask the disorder and, in many cases, life-saving treatment can be as simple as a lifestyle change—perhaps taking medication or avoiding high-level sports.”
Some people, she adds, may need an implantable cardioverter-defibrillator, similar to a pacemaker, to prevent their heart from going into a dangerous rhythm.
Dewar also wants to educate family physicians and the general public to be aware of the subtle signs of heart rhythm disorders, such as palpitations, chest pain and/or episodes of syncope or near-syncope (fainting and near-fainting).
“When a child says “my heart feels funny” after running up the stairs, it shouldn’t be ignored. It could be a flag for an underlying heart disorder. Treatment, not just for the child’s sake, but for the whole family, can be life-saving.”
Link to study: http://i.sfu.ca/eiRUEr
Laura Dewar, kinesiology, 250.395.0020, firstname.lastname@example.org